The present disclosure relates generally to downhole power generation systems and methods and, more particularly, to downhole power generation systems and methods that utilize hydraulic fluid flow regulation to generate electrical power.
Modern hydrocarbon drilling and production operations can often require that electrical power be supplied to equipment in the downhole environment. For example, electrical power is required downhole for a number of applications, including well logging and telemetry. Well logging of the borehole often includes the use of active sensors that require power to obtain information about the downhole environment. Such information will typically include the various characteristics and parameters of the earth formations traversed by the borehole, data relating to the size and configuration of the borehole itself, pressures and temperatures of ambient downhole fluids, and other vital downhole parameters. Telemetry commonly utilizes electrical power to relay data acquired from various logging sensors in the downhole environment to the surface.
The supply and generation of electrical power downhole, however, can be problematic for a number of reasons. For instance, the storage of electrical power in certain regions of the wellbore can be problematic due to high temperatures and other harsh conditions that are outside the operational limits of conventional batteries and capacitors.
One approach to generating power downhole utilizes the circulating drilling fluid (or “mud”) which serves to operate a downhole generator or turbine. At least one problem with this approach is that when the mud flow ceases, downhole power production capabilities are lost, and some downhole applications require electrical power even in the absence of mud flow. Additionally, due to the potential extreme flow rates that the circulating mud may attain, any such generator or turbine is typically oversized relative to generators and turbines used with typical mud flow rates. The increased size of the generator or turbine leads to lower than optimal efficiency and increased cost. There is currently no adequate resolution for this issue in regions of the wellbore in which power currently cannot be satisfactorily stored or delivered.